DECC$EFS_FILE_TIMESTAMPS

   With DECC$EFS_FILE_TIMESTAMPS enabled, stat and fstat report
   new ODS-5 access time (st_atime), attribute revision time 
   (st_ctime) and modification time (st_mtime) for files on ODS-5
   volumes that have the extended file times enabled using SET
   VOLUME/VOLUME=ACCESS_DATES.

   If DECC$EFS_FILE_TIMESTAMPS is disabled, or the volume is not
   ODS-5, or the volume does not have support for these additional
   times enabled, st_ctime continues to be the file creation time
   and st_atime the same as the st_mtime.

   The utime and utimes functions support these ODS-5 times in the
   same way as stat.